Resorption of the formed elements 75 



not really serve to seize foreign bodies and carry them into the cell 

 contents. It appears to us that sometimes they undoubtedly do fulfil 

 this function. For example, it is only by means of such amoeboid 

 movements that leprosy bacilli can be introduced into the interior of 

 ganglion cells and cells of the spinal cord 1 . We must not dwell 

 on this question, as the phagocytic property of the nerve elements 

 plays no part in the resorption of cells. On the other hand, the 

 neuroglia cells contribute largely to this process and their phagocytic 

 function is now admitted by many observers 2 . 



For long the large " dust " cells of the respiratory channels were 

 looked upon as being epithelial cells which were capable of ingesting 

 carbon particles, micro-organisms and other foreign bodies. The re- 

 searches of N. Tchistovitch, carried out in my laboratory more than 

 twelve years ago, made it evident that these elements are nothing 

 more than white corpuscles that have immigrated into the alveoli 

 and bronchi. 



It is probable that the same is the case as regards the stellate cells 

 of the liver, known as Kupffer's cells. First described by Kupfler 

 as cells of a nervous type, having long processes, they were later 

 recognised by several observers as belonging to the endothelial [81] 

 tissue of the blood vessels of the liver. Kupffer 3 himself has ac- 

 cepted this view and in his recently published monograph on these 

 stellate cells, he describes them as endothelial cells that have 

 retained their independence. Some researches on the resorption 

 of blood, of which I shall speak shortly, have led me to think 

 that these cells are nothing but white corpuscles that have been 

 arrested in the hepatic capillaries. I have asked Mesnil, head of 

 my laboratory, to study this question for me. His investigation is not 

 yet concluded, but the demonstration already made that the livers 

 of guinea-pig embryos and new-born rabbits do not possess any 

 KupiFer's cells is an argument in favour of my hypothesis. 



Certain white corpuscles have undoubtedly been often mistaken 

 for epithelial or connective tissue cells. We must not conclude from 

 this, however, that these elements are never capable of sending out 

 amoeboid processes and of ingesting foreign bodies. It would, how- 

 ever, be useful to collect new and incontestable proofs of the 



1 Soudake witch, Ziegler's Beitr. z. path. Anat., Jena, 1888, Bd. n, S. 129, and 

 Babes, " Untersuchungen iiber den Leprabacillus," Berlin, 1898, S. 58. 



2 Marinesco, Compt. rend. Soc. de Jliol., Paris, 1896, p. 726. 



3 Arch.f. mikr. Anat., Bonn, 1899, Bd. LIV, S. 254. 



